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Joo SY, Jang SH, Kim JA, Kim SJ, Kim B, Kim HY, Choi JY, Gee HY, Jung J. Prevalence and Clinical Characteristics of Mitochondrial DNA Mutations in Korean Patients With Sensorineural Hearing Loss. J Korean Med Sci 2023; 38:e355. [PMID: 38084023 PMCID: PMC10713439 DOI: 10.3346/jkms.2023.38.e355] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/12/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Mutations in mitochondrial DNA (mtDNA) are associated with several genetic disorders, including sensorineural hearing loss. However, the prevalence of mtDNA mutations in a large cohort of Korean patients with hearing loss has not yet been investigated. Thus, this study aimed to investigate the frequency of mtDNA mutations in a cohort of with pre- or post-lingual hearing loss of varying severity. METHODS A total of 711 Korean families involving 1,099 individuals were evaluated. Six mitochondrial variants associated with deafness (MTRNR1 m.1555A>G, MTTL1 m.3243A>G, MTCO1 m.7444G>A and m.7445A>G, and MTTS1 m.7471dupC and m.7511T>C) were screened using restriction fragment length polymorphism. The prevalence of the six variants was also analyzed in a large control dataset using whole-genome sequencing data from 4,534 Korean individuals with unknown hearing phenotype. RESULTS Overall, 12 of the 711 (1.7%) patients with hearing loss had mtDNA variants, with 10 patients from independent families positive for the MTRNR1 m.1555A>G mutation and 2 patients positive for the MTCO1 m.7444G>A mutation. The clinical characteristics of patients with the mtDNA variants were characterized by post-lingual progressive hearing loss due to the m.1555A>G variant (9 of 472; 1.9%). In addition, 18/4,534 (0.4%) of the Korean population have mitochondrial variants associated with hearing loss, predominantly the m.1555A>G variant. CONCLUSION A significant proportion of Korean patients with hearing loss is affected by the mtDNA variants, with the m.1555A>G variant being the most prevalent. These results clarify the genetic basis of hearing loss in the Korean population and emphasize the need for genetic testing for mtDNA variants.
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Affiliation(s)
- Sun Young Joo
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
| | - Seung Hyun Jang
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
| | - Jung Ah Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
| | - Se Jin Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
| | - Bonggi Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Hye-Youn Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
| | - Jae Young Choi
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Heon Yung Gee
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea.
| | - Jinsei Jung
- Won-Sang Lee Institute for Hearing Loss, Seoul, Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.
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Peng W, Zhong Y, Zhao X, Yuan J. Low penetrance of hearing loss in two Chinese families carrying the mitochondrial tRNASer(UCN) mutations. Mol Med Rep 2020; 22:77-86. [PMID: 32377700 PMCID: PMC7248462 DOI: 10.3892/mmr.2020.11100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 02/20/2020] [Indexed: 01/07/2023] Open
Abstract
Mutations in mitochondrial DNA (mtDNA), especially in mitochondrial 12S rRNA and transfer RNA(tRNA)Ser(UCN) genes, are important causes of non-syndromic hearing loss. However, the molecular mechanism underlying mt-tRNA mutations in clinical hearing impairment are not fully understood. The present study assessed the molecular characterization of two Chinese families with non-syndromic hearing loss, who both exhibited very low penetrance of deafness (9.1 and 12.5% for Family 1 and 2, respectively). Mutational analysis of the complete mtDNA genes identified the presence of cytochrome c oxidase 1/tRNASer(UCN) G7444A and tRNASer(UCN) C7492T mutations, together with polymorphisms belonging to human mitochondrial haplogroup D4 and G2b, respectively. Moreover, the G7444A and C7492T mutations occurred at highly conserved tRNASer(UCN) nucleotides and may cause tRNA metabolism failure, which is involved in mitochondrial translation defects. Therefore, the G7444A and C7492T mutations may lead to the mitochondrial dysfunction that responsible for deafness. However, the absence of any functional variants in Gap junction β-2, Solute Carrier Family 26 Member 4 and TRNA 5-methylaminomethyl-2-thiouridylate methyltransferase suggested that nuclear genes may not play active roles in the occurrence of deafness. In the present study, the observed incomplete penetrance of hearing loss and mild mitochondrial dysfunction indicated that mtDNA G7444A and C7492T mutations are insufficient to produce the deafness phenotype. Therefore, other risk factors such as environmental factors and epigenetic regulation may be involved in the pathogenesis of hearing loss in the families recruited in the present study.
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Affiliation(s)
- Wei Peng
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yi Zhong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Xueyan Zhao
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jie Yuan
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
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Zheng J, Bai X, Xiao Y, Ji Y, Meng F, Aishanjiang M, Gao Y, Wang H, Fu Y, Guan MX. Mitochondrial tRNA mutations in 887 Chinese subjects with hearing loss. Mitochondrion 2020; 52:163-172. [PMID: 32169613 DOI: 10.1016/j.mito.2020.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/13/2020] [Accepted: 03/09/2020] [Indexed: 01/24/2023]
Abstract
Mutations in the mitochondrial tRNAs have been reported to be the important cause of hearing loss. However, only a few cases have been identified thus far and the prevalence of mitochondrial tRNA mutations in hearing-impaired patients remain unclear. Here we performed the mutational analysis of 22 mitochondrial tRNA genes in a large cohort of 887 Han Chinese subjects with hearing loss by Sanger sequencing. The systemic evaluation of putative pathogenic variants was further carried out by frequency in controls (<1%), phylogenetic analysis, structural analysisandfunctionalprediction. As a result, a total of 147 variants on 22 tRNA genes were identified. Among these, 39 tRNA mutations (10 pathogenic and 29 likely pathogenic) which absent or present <1% in 773 Chinese controls, localized at highly conserved nucleotides, or changed the modified nucleotides, could have potential structural alterations and functional significance, thereby considered to be deafness-associated mutations. Furthermore, 44 subjects carried one of these 39 pathogenic/likely pathogenic tRNA mutations with a total prevalence of 4.96%. However, the phenotypic variability and incomplete penetrance of hearing loss in pedigrees carrying these tRNA mutations indicate the involvement of modifier factors, such as nuclear encoded genes associated with mitochondrion biogenesis, mitochondrial haplotypes, epigenetic and environmental factors. Thus, our data provide the evidence that mitochondrial tRNA mutations are the important causes of hearing loss among Chinese population. These findings further increase our knowledge on the clinical relevance of tRNA mutations in the mitochondrial genome, and should be helpful to elucidate the pathogenesis of maternal hearing loss.
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Affiliation(s)
- Jing Zheng
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Bai
- Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Yun Xiao
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Maerhaba Aishanjiang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yinglong Gao
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Haibo Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China.
| | - Yong Fu
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Department of Otorhinolaryngology Head and Neck Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China.
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
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Moassass F, Al-Halabi B, Nweder MS, Al-Achkar W. Investigation of the mtDNA mutations in Syrian families with non-syndromic sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2018; 113:110-114. [PMID: 30173967 DOI: 10.1016/j.ijporl.2018.07.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Hearing loss is a common sensory disorder, and at least 50% of cases are due to a genetic etiology. Several mitochondrial DNA mutations (mtDNA) have been reported to be associated with nonsyndromic hearing loss (NSHL) in different population. However, There is no previous available data about the frequency of mtDNA mutations as etiology for deafness in Syrian. The aim of present study is to investigate the incidence of common mt DNA mutations in our families with congenital hearing loss and not related to the ototoxicity or aminoglycosides. METHODS A total of 50 deaf families were enrolled in the present study. Direct sequencing and PCR-RFLP methods were employed to detect seven mt DNA mutations, including A1555G, A3243G, C1494T, G3316A, T7510C, A7445G, and 7472insC. RESULTS Our results revealed a high prevalence of mt DNA mutation (10%) in deaf families (5/50). In surprising, the unexpected mutations were observed. The G3316A mutation was found in 2 families as homoplasmic genotype. Also, we found the homoplasmic and heteroplasmic genotype for the C1494T mutation in two families. In one family the heteroplasmic genotype for T7510C mutation was observed; this family harbor 35delG mutation in GJB2 gene. None of the common mtDNA mutations (A1555G, A3243G) and other mutations (A7445G, 7472insC) were detected here. CONCLUSION Our findings indicate to significant contribution of the mt DNA mutations in our families with NSHL. The presented data is the first report about mt DNA and it will improve the genetic counseling of hearing impaired in Syrian families.
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Affiliation(s)
- Faten Moassass
- Human Genetics Division, Molecular Biology and Biotechnology Department, Atomic Energy Commission, Damascus, Syria
| | - Bassel Al-Halabi
- Human Genetics Division, Molecular Biology and Biotechnology Department, Atomic Energy Commission, Damascus, Syria
| | - Mohamad Sayah Nweder
- Human Genetics Division, Molecular Biology and Biotechnology Department, Atomic Energy Commission, Damascus, Syria
| | - Walid Al-Achkar
- Human Genetics Division, Molecular Biology and Biotechnology Department, Atomic Energy Commission, Damascus, Syria.
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Jiang H, Chen J, Li Y, Lin PF, He JG, Yang BB. Prevalence of mitochondrial DNA mutations in sporadic patients with nonsyndromic sensorineural hearing loss. Braz J Otorhinolaryngol 2016; 82:391-6. [PMID: 26873147 PMCID: PMC9449052 DOI: 10.1016/j.bjorl.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 05/16/2015] [Accepted: 06/06/2015] [Indexed: 10/28/2022] Open
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Zheng J, Sha-sha G, Xiao-wen T, Yi Z, Min-xin G. Human Mitochondrial tRNA Mutations in Maternally Inherited Deafness. J Otol 2013. [DOI: 10.1016/s1672-2930(13)50006-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Ding Y, Leng J, Fan F, Xia B, Xu P. The role of mitochondrial DNA mutations in hearing loss. Biochem Genet 2013; 51:588-602. [PMID: 23605717 DOI: 10.1007/s10528-013-9589-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/10/2012] [Indexed: 11/29/2022]
Abstract
Mutations in mitochondrial DNA (mtDNA) are one of the most important causes of hearing loss. Of these, the homoplasmic A1555G and C1494T mutations at the highly conserved decoding site of the 12S rRNA gene are well documented as being associated with either aminoglycoside-induced or nonsyndromic hearing loss in many families worldwide. Moreover, five mutations associated with nonsyndromic hearing loss have been identified in the tRNA(Ser(UCN)) gene: A7445G, 7472insC, T7505C, T7510C, and T7511C. Other mtDNA mutations associated with deafness are mainly located in tRNA and protein-coding genes. Failures in mitochondrial tRNA metabolism or protein synthesis were observed from cybrid cells harboring these primary mutations, thereby causing the mitochondrial dysfunctions responsible for deafness. This review article provides a detailed summary of mtDNA mutations that have been reported in deafness and further discusses the molecular mechanisms of these mtDNA mutations in deafness expression.
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Affiliation(s)
- Yu Ding
- Central Laboratory, Hangzhou First People's Hospital, Nanjing Medical University, Huansha Road, Hangzhou, China.
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8
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A novel MT-CO1 m.6498C>A variation associated with the m.7444G>A mutation in the mitochondrial COI/tRNASer(UCN) genes in a patient with hearing impairment, diabetes and congenital visual loss. Biochem Biophys Res Commun 2013; 430:585-91. [DOI: 10.1016/j.bbrc.2012.11.109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 11/19/2012] [Indexed: 11/18/2022]
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Non-syndromic Hearing Impairment in a Hungarian Family with the m.7510T>C Mutation of Mitochondrial tRNA(Ser(UCN)) and Review of Published Cases. JIMD Rep 2012; 9:105-111. [PMID: 23430555 DOI: 10.1007/8904_2012_187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 04/06/2023] Open
Abstract
The m.7510T>C mitochondrial DNA (mtDNA) mutation is a tRNA(Ser(UCN)) alteration leading to matrilineal isolated hearing impairment. The current paper reviews the available reports on the m.7510T>C mtDNA mutation, with special attention to phenotypic variations and haplogroup background. A Hungarian family, the fourth family reported in the literature, is presented, in which analysis of three generations with bilateral isolated hearing loss revealed the m.7510T>C tRNA(Ser(UCN)) mutation in homoplasmic form in the affected members. Haplogroup analysis verified an unnamed subgroup of mitochondrial haplogroup H. Previously reported Spanish and North American Caucasian families belong to different subgroups of haplogroup H. Analyzing our biobank of Hungarian patients with sensorineural hearing loss, we did not detect this mutation in any other patient, nor was it found in Caucasian haplogroup H control samples. Comparing the cases reported so far, there is interfamilial variablity in the age of onset, accompanying symptoms, and haplogroup background. Our case adds further genetic evidence for the pathogenicity of the m.7510T>C mutation and underlines the need to include full mtDNA sequencing in the screening for unexplained hearing loss.
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Jing Z, Yan–chun J, Min–Xin G. Mitochondrial tRNA mutations associated with deafness. J Otol 2012. [DOI: 10.1016/s1672-2930(12)50009-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Zheng J, Ji Y, Guan MX. Mitochondrial tRNA mutations associated with deafness. Mitochondrion 2012; 12:406-13. [PMID: 22538251 DOI: 10.1016/j.mito.2012.04.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 03/15/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
Abstract
Mitochondrial tRNA mutations are one of the important causes of both syndromic and non-syndromic deafness. Of those, syndromic deafness-associated tRNA mutations such as tRNA(Leu(UUR)) 3243A>G are often present in heteroplasmy, while non-syndromic deafness-associated tRNA mutations including tRNA(Ser(UCN)) 7445A>G often occur in homplasmy or in high levels of heteroplasmy. These tRNA mutations are the primary mutations leading to hearing loss. However, other tRNA mutations such as tRNA(Thr) 15927G>A and tRNA(Ser(UCN)) 7444G>A may act in synergy with the primary mitochondrial DNA mutations, modulating the phenotypic manifestation of the primary mitochondrial DNA mutations. Theses tRNA mutations cause structural and functional alteration. A failure in tRNA metabolism caused by these tRNA mutations impaired mitochondrial translation and respiration, thereby causing mitochondrial dysfunctions responsible for deafness. These data offer valuable information for the early diagnosis, management and treatment of maternally inherited deafness.
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Affiliation(s)
- Jing Zheng
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Rydzanicz M, Cywińska K, Wróbel M, Pollak A, Gawęcki W, Wojsyk-Banaszak I, Lechowicz U, Mueller-Malesińska M, Ołdak M, Płoski R, Skarżyński H, Szyfter K, Szyfter W. The contribution of the mitochondrial COI/tRNA(Ser(UCN)) gene mutations to non-syndromic and aminoglycoside-induced hearing loss in Polish patients. Mol Genet Metab 2011; 104:153-9. [PMID: 21621438 DOI: 10.1016/j.ymgme.2011.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/08/2011] [Accepted: 05/08/2011] [Indexed: 11/17/2022]
Abstract
Mutations in mitochondrial DNA have been implicated in both, non-syndromic and aminoglycoside-induced hearing loss. In the present study, we have performed the systematic mutation screening of the COI/tRNA(Ser(UCN)) genes in 250 unrelated Polish subjects with hearing impairment. Three different homoplasmic sequence variants were identified, including one common polymorphism m.7476 C>T in tRNA(Ser(UCN)) and two mutations, m.7444 G>A and m.7445 A>G localized in the COI/precursor of tRNA(Ser(UCN)). The incidence of m.7444 G>A substitution was estimated at 1.6% (4/250), however variable penetrance of hearing loss, age of onset and hearing thresholds among m.7444 G>A carriers was observed. Two subjects had the positive history of aminoglycoside exposure and one of them harbored both m.7444 G>A and 12S rRNA m.1555 A>G mutations. Those suggest that m.7444 G>A itself is not sufficient to produce a clinical phenotype and additional modifier factors are required for pathogenic manifestation of m.7444 G>A substitution. Moreover, we have described the first Polish family with non-syndromic hearing loss, harboring m.7445 A>G mutation. The penetrance of hearing loss in this pedigree was 58% when aminoglycoside-induced hearing impairment was included, and 8% when ototoxic effect was excluded. This finding strongly suggests the possible role of m.7445 A>G in susceptibility to aminoglycoside induced-hearing loss.
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Affiliation(s)
- Małgorzata Rydzanicz
- Institute of Human Genetics, Polish Academy of Sciences, Strzeszyńska 32, 60-479 Poznań, Poland.
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Chen J, Yuan H, Lu J, Liu X, Wang G, Zhu Y, Cheng J, Wang X, Han B, Yang L, Yang S, Yang A, Sun Q, Kang D, Zhang X, Dai P, Zhai S, Han D, Young WY, Guan MX. Mutations at position 7445 in the precursor of mitochondrial tRNASer(UCN) gene in three maternal Chinese pedigrees with sensorineural hearing loss. Mitochondrion 2008; 8:285-92. [DOI: 10.1016/j.mito.2008.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 05/06/2008] [Accepted: 05/14/2008] [Indexed: 10/22/2022]
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Abstract
More than 200 disease-related mitochondrial DNA (mtDNA) point mutations have been reported in the Mitomap (http://www.mitomap.org) database. These mutations can be divided into two groups: mutations affecting mitochondrial protein synthesis, including mutations in tRNA and rRNA genes; and mutations in protein-encoding genes (mRNAs). This review focuses on mutations in mitochondrial genes that encode proteins. These mutations are involved in a broad spectrum of human diseases, including a variety of multisystem disorders as well as more tissue-specific diseases such as isolated myopathy and Leber hereditary optic neuropathy (LHON). Because the mitochondrial genome contains a large number of apparently neutral polymorphisms that have little pathogenic significance, along with secondary homoplasmic mutations that do not have primary disease-causing effect, the pathogenic role of all newly discovered mutations must be rigorously established. A scoring system has been applied to evaluate the pathogenicity of the mutations in mtDNA protein-encoding genes and to review the predominant clinical features and the molecular characteristics of mutations in each mtDNA-encoded respiratory chain complex.
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Affiliation(s)
- Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB2015, Houston, Texas 77030, USA.
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Jin L, Yang A, Zhu Y, Zhao J, Wang X, Yang L, Sun D, Tao Z, Tsushima A, Wu G, Xu L, Chen C, Yi B, Cai J, Tang X, Wang J, Li D, Yuan Q, Liao Z, Chen J, Li Z, Lu J, Guan MX. Mitochondrial tRNASer(UCN) gene is the hot spot for mutations associated with aminoglycoside-induced and non-syndromic hearing loss. Biochem Biophys Res Commun 2007; 361:133-9. [PMID: 17659260 DOI: 10.1016/j.bbrc.2007.06.171] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 06/29/2007] [Indexed: 10/23/2022]
Abstract
Mutations in mitochondrial DNA is one of the important causes of hearing loss. Here, we performed a mutational screening of tRNA(Ser(UCN)) gene in 1542 Chinese subjects with hearing loss. One subject and five subjects carried tRNA(Ser(UCN)) A7445C and G7444A mutations, respectively, while two subjects harbored both G7444A and 12S rRNA A1555G mutations. Clinical evaluation revealed the variable phenotype of bilateral hearing impairment including severity and audiometric configuration in these subjects. Six pedigrees carrying only G7444A or A7445C mutation exhibited extremely low penetrance of hearing loss, while two families carrying both G7444A and A1555G mutations displayed high penetrance of hearing loss. Of 94 matrilineal relatives in these families, eight subjects suffered from aminoglycoside-induced hearing loss, while seven hearing-impaired subjects did not have a history of exposure to aminoglycosides. Those suggest that G7444A and A7445C mutations themselves are insufficient to produce a clinical phenotype and aminoglycosides are the major modifier factors for the development of deafness in these Chinese families. The combination of A1555G and G7444A mutations increased deafness expression. These observations provide an additional evidence for the early diction and prevention of deafness at the high risk populations carrying these mitochondrial DNA mutations.
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Affiliation(s)
- Longjin Jin
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Abstract
The human ear is a delicate sensory apparatus of hearing for normal communication, and its proper functioning is highly dependent on mitochondrial oxidative phosphorylation. The first mitochondrial point mutation for nonsyndromic and aminoglycoside-induced hearing loss was identified in 1993. Since then a number of inherited mitochondrial mutations have been implicated in hearing loss. Most of the molecular defects responsible for mitochondrial disorder-associated hearing loss are mutations in the 12S rRNA gene and tRNA genes. In this review, after a short description of normal hearing mechanisms and mitochondrial genetics, we outline the recent advances that have been made in the identification of deafness-associated mitochondrial mutations, and discuss how mitochondrial dysfunction contributes to hearing loss.
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Affiliation(s)
- Guangqian Xing
- Department of Otolaryngology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
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Wong LJC. Diagnostic challenges of mitochondrial DNA disorders. Mitochondrion 2006; 7:45-52. [PMID: 17276740 DOI: 10.1016/j.mito.2006.11.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 10/23/2006] [Indexed: 10/23/2022]
Abstract
Although mitochondrial disorders are increasingly being recognized, confirming a specific diagnosis remains a great challenge due to the genetic and clinical heterogeneity of the disease. The heteroplasmic nature of most pathogenic mitochondrial DNA mutations and the uncertainties of the clinical significance of novel mutations pose additional complications in making a diagnosis. Suspicion of mitochondrial disease among patients with multiple, seemingly unrelated neuromuscular and multi-system disorders should ideally be confirmed by the finding of deleterious mutations in genes involving mitochondrial biogenesis and functions. The genetics are complex, as the primary mutation can be either in the nuclear or the mitochondrial DNA (mtDNA). MtDNA mutations are often maternally inherited, but can also be sporadic or secondary to mutations in nuclear-encoded mitochondrial-targeted genes. Several well-defined clinical syndromes associated with specific mutations have been described, yet the genotype-phenotype correlation is often unclear and most patients do not fit within any defined syndrome and even within a family the expressivity of the disease can be extremely variable. This article describes examples representing diagnostic challenges of mitochondrial diseases that include the limitations of the mutation detection method, the occurrence of mitochondrial disease in families with another known neuromuscular disorder, atypical clinical presentation, the lack of correlation between the degree of mutant heteroplasmy and the severity of the disease, variable penetrance, and nuclear gene defects causing mtDNA depletion.
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Affiliation(s)
- Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB 2015, Houston, TX 77030, USA.
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Zhu Y, Qian Y, Tang X, Wang J, Yang L, Liao Z, Li R, Ji J, Li Z, Chen J, Choo DI, Lu J, Guan MX. Aminoglycoside-induced and non-syndromic hearing loss is associated with the G7444A mutation in the mitochondrial COI/tRNASer(UCN) genes in two Chinese families. Biochem Biophys Res Commun 2006; 342:843-50. [PMID: 16500624 DOI: 10.1016/j.bbrc.2006.02.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 02/07/2006] [Indexed: 11/23/2022]
Abstract
We report here the clinical, genetic, and molecular characterization of two Chinese families with aminoglycoside induced and non-syndromic hearing impairment. Clinical and genetic evaluations revealed the variable severity and age-of-onset in hearing impairment in these families. Strikingly, there were extremely low penetrances of hearing impairment in these Chinese families. Sequence analysis of the complete mitochondrial genomes in these pedigrees showed the distinct sets of mtDNA polymorphism, in addition to the identical G7444A mutation associated with hearing loss. Indeed, the G7444A mutation in the CO1 gene and the precursor of tRNASer(UCN) gene is present in homoplasmy only in the maternal lineage of those pedigrees but not other members of these families and 164 Chinese controls. Their mitochondrial genomes belong to the Eastern Asian haplogroups C5a and D4a, respectively. In fact, the occurrence of the G7444A mutation in these several genetically unrelated subjects affected by hearing impairment strongly indicates that this mutation is involved in the pathogenesis of hearing impairment. However, there was the absence of other functionally significant mtDNA mutations in two Chinese pedigrees carrying the G7444A mutation. Therefore, nuclear modifier gene(s) or aminoglycoside(s) may play a role in the phenotypic expression of the deafness-associated G7444A mutation in these Chinese pedigrees.
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Affiliation(s)
- Yi Zhu
- Department of Otolaryngology and Zhejiang Provincial Key Laboratory of Medical Genetics, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Yuan H, Qian Y, Xu Y, Cao J, Bai L, Shen W, Ji F, Zhang X, Kang D, Mo JQ, Greinwald JH, Han D, Zhai S, Young WY, Guan MX. Cosegregation of the G7444A mutation in the mitochondrial COI/tRNA(Ser(UCN)) genes with the 12S rRNA A1555G mutation in a Chinese family with aminoglycoside-induced and nonsyndromic hearing loss. Am J Med Genet A 2005; 138A:133-40. [PMID: 16152638 PMCID: PMC2759106 DOI: 10.1002/ajmg.a.30952] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We report here on the characterization of a three-generation Chinese family with aminoglycoside-induced and nonsyndromic hearing impairment. Ten of 17 matrilineal relatives exhibited bilateral and sensorineural hearing impairment. Of these, nine matrilineal relatives, who had a history of exposure to aminoglycosides, exhibited variable severity and audiometric configuration of hearing loss. The dose and age at the time of drug administration seemed to be correlated with the severity of the hearing loss experienced by affected individuals. Sequence analysis of the complete mitochondrial genome in the pedigree showed the presence of homoplasmic A1555G mutation and 37 variants belonging to haplogroup D4a. Of those variants, the G7444A mutation is of special interest as the mutation at this position results in a read-through of the stop condon AGA of the COI message, thereby adding three amino acids (Lys-Gln-Lys) to the C-terminal of the polypeptide. Alternatively, the G7444A mutation is adjacent to the site of 3' end endonucleolytic processing of L-strand RNA precursor, spanning tRNA(Ser(UCN)) and ND6 mRNA. Thus, the G7444A mutation, similar to the deafness-associated A7445G mutation, may lead to a defect in the processing of the L-strand RNA precursor, thus influencing the phenotypic expression of the A1555G mutation. These data also imply that nuclear background plays a role in the aminoglycoside ototoxicity associated with the A1555G mutation in this Chinese pedigree.
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Affiliation(s)
- Huijun Yuan
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Yaping Qian
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Yanjun Xu
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Juyang Cao
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Linna Bai
- Jiangxi Rehabilitation Center for Disabled Persons, Nanchang, JiangXi, China
| | - Weidong Shen
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Fei Ji
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Xin Zhang
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Dongyang Kang
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Jun Qin Mo
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - John H. Greinwald
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Dongyi Han
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Suoqiang Zhai
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Wie-Yen Young
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- Corresponding authors: Min-Xin Guan, Ph.D., Division and Program in Human Genetics, Cincinnati Children’s Hospital Medical, Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039, USA, Telephone: (513) 636-3337; FAX: (513) 636-3486; E-mail: , Wie-Yen Young, MD, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Min-Xin Guan
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Corresponding authors: Min-Xin Guan, Ph.D., Division and Program in Human Genetics, Cincinnati Children’s Hospital Medical, Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039, USA, Telephone: (513) 636-3337; FAX: (513) 636-3486; E-mail: , Wie-Yen Young, MD, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
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Zhao H, Young WY, Yan Q, Li R, Cao J, Wang Q, Li X, Peters JL, Han D, Guan MX. Functional characterization of the mitochondrial 12S rRNA C1494T mutation associated with aminoglycoside-induced and non-syndromic hearing loss. Nucleic Acids Res 2005; 33:1132-9. [PMID: 15722487 PMCID: PMC549421 DOI: 10.1093/nar/gki262] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we report the biochemical characterization of the deafness-associated mitochondrial 12S rRNA C1494T mutation using 27 cybrid cell lines constructed by transferring mitochondria from 9 lymphoblastoid cell lines derived from a Chinese family into human mitochondrial DNA (mtDNA)-less (ρ°) cells. Six cybrids derived from two asymptomatic members, and nine cybrids derived from three symptomatic members of the Chinese family carrying the C1494T mutation exhibited ∼38 and 43% decrease in the rate of mitochondrial protein labeling, respectively, compared with twelve cybrids derived from four Chinese control individuals. These defects are apparently a primary contributor to significant reductions in the rate of overall respiratory capacity or the rate of malate/glutamate promoted respiration, or succinate/G3P-promoted respiration, or TMPD/ascorbate-promoted respiration in mutant cybrid cell lines derived from either symptomatic or asymptomatic individuals. Furthermore, the very significant/nearly identical increase in the ratio of doubling times in DMDM medium in the presence/absence of high concentration of paromomycin was observed in symptomatic or asymptomatic cybrid cell lines carrying the C1494T mutation as compared with the average rate in control cell lines. These observations provide the direct biochemical evidences that the C1494T mutation is a pathogenic mtDNA mutation associated with aminoglycoside-induced and non-syndromic hearing loss. In addition, these data provide the first biochemical evidence that nuclear background plays a critical role in the phenotypic manifestation of non-syndromic hearing loss and aminoglycoside toxicity associated with the C1494T mutation.
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Affiliation(s)
- Hui Zhao
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
| | - Wie-Yen Young
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
| | - Qingfeng Yan
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
| | - Ronghua Li
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
| | - Juyang Cao
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
| | - Qiuju Wang
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
| | - Xiaoming Li
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
| | - Jennifer L. Peters
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
| | - Dongyi Han
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
| | - Min-Xin Guan
- Division and Program in Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General HospitalBeijing 100853, China
- To whom correspondence should be addressed. Tel: +1 513 636 3337; Fax: +1 513 636 2261;
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